Chemometrics characterization of The Llobregat river dissolved organic matter

• Published in: Chemometrics and intelligent laboratory systems Vol. 201; p. 104018
• Main Authors: Marín-García, Marc, Tauler, Romà
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.06.2020
• Subjects: Dissolved organic matter (DOM); Excitation-emission matrix (EEM); Molecular fluorescence spectroscopy; Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS); River water; UV spectrophotometry; Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS); Dissolved organic matter (DOM); Excitation-emission matrix (EEM); Molecular fluorescence spectroscopy; UV spectrophotometry; River water
• ISSN: 0169-7439; 1873-3239
• DOI: 10.1016/j.chemolab.2020.104018

The potential use of multivariate chemometric methods for the investigation of the dissolved organic matter (DOM) sources in surface river waters monitored by UV absorbance and excitation-emission fluorescence spectroscopy is shown. The Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) method is applied to the analysis of the excitation-emission multidimensional data matrices acquired at ten different river sampling sites along the basin of the Llobregat river (located at the north-west of the Iberian Peninsula), from its origin to its mouth, during three different monitoring campaigns. The results obtained by MCR-ALS provided information about the compositional changes of the different DOM sources (i.e. humic-, fulvic- or protein-like sources) present in the investigated river samples, about their site distribution along the river basin and about their changes in three different monitoring campaigns. Eight different MCR-ALS components were resolved describing several types of DOM, with different excitation and emission spectra and with distinct distribution profiles along the river sampling sites. A comparative study of each single sampling site describing the changes in their DOM composition during the three monitoring campaigns was also performed. (A) Sampling points and UV-Visible spectra, (B) MCR-ALS bilinear decomposition example and compositional information of the DOM present in Point P. [Display omitted] •DOM sources in the surface waters of the Llobregat river are investigated by UV spectrophotometry and fluorescence spectroscopy and chemometric analysis.•A powerful data processing tool for the analysis of the EEM data from multiple samples is proposed using the MCR-ALS method.•Implementation of the trilinearity constraint in the MCR-ALS analysis of multiple EEM data matrices is shown.•Eight different MCR-ALS components were resolved.•Several types of DOM, with different EX and EM spectra and with distinct river distribution profiles were described.